1. Field of the Invention
This invention relates generally to a gas sensor for detecting the presence of hydrogen in gas streams or environments comprising same, as well as to an appertaining methodology for sensing the presence of hydrogen gas in such gas streams or environments.
2. Description of the Related Art
About one-half of all the sensors used to measure hazardous gases measure hydrogen. The bulk of these systems utilize as the detector element a Group VIIIB metal element (Ni, Pd, Pt) that is heated to catalytically oxidize the hydrogen, with the resulting change in heat load being the measured parameter for determination of the presence of hydrogen.
Sensors of such "hot wire" type have cross-sensitivity to other easily oxidized materials, such as alcohols and hydrocarbons. Such easily oxidized materials are common components of gases in a semiconductor manufacturing environment, and in such application the result is frequent occurrence of false alarms.
Since the current generation of hot wire sensors require an oxidation reaction for operation, such sensors are unable to detect hydrogen when it is present in inert gas streams or environments which are not of a character to support oxidative reaction. This is a severe deficiency of such hot wire sensors and limits their applicability and utility.
It would be a significant advance in the art to provide a sensor overcoming the aforementioned deficiencies of current hot wire sensors.
It therefore is an object of the present invention to provide a sensor system that is sensitive to the presence of hydrogen in the gas being monitored, and does not sense the presence of other oxidizable compounds, and which additionally is operable to sense the presence of hydrogen in inert gases or gas streams or environments that do not support oxidization.
Other objects and advantages of the present invention will be more fully apparent from the ensuing disclosure and appended claims.